I have read othre threads here about problems with Zoyzia grass dying out and we are having the same problem. The dead grass is contributing to the thach. SO over the weekend I raked alot of the thatch up and what I was finding was a number of black...I mean real black bugs that look like a beetle runnning around. Imean these critters are very small but you can find them due to therir black color contrasted against the brown thatch.
SO what I am saying is that I dont think I have Brown Spot but Billbugs in my grass. To find them just stare at the grass and you may notice something crawling in the thatch. Here is a good link in identifying them.
http://www.american-lawns.com/insects/billbugs.html
Anyone else have this problem...How did you get rid of them?????